Counting preseason, the Bills have used 4 quarterbacks now and all of them have struggled. McCarron in preseason did not look good either. Josh Allen shouldn't have been thrust in as the starter in week 2, but easy to see why he was. A couple weeks here watching the game will help him, but Bills offense and lack of playmakers is going to restrict anyones success.
Dak Prescott had much better stats his rookie year than his 2nd year. Jared Goff looked like he could barely throw the ball 20 yards his rookie year and he's looking really good now. Anyone who's been watching the NFL for a long time knows that you simply cannot accurately rate a rookie quarterback based on their first year. Tom Brady played in ONE freaking game his whole rookie year, for only a few plays. Obviously no way to know then how he would end up.